1. Field of the Invention
This invention relates to a cooling fan and a cooling fan assembly which are used for cooling an object.
2. Description of Related Art
Cooling fans are widely utilized to cool the air surrounding electrical circuits in electronic apparatuses. For example, cooling fans are used in personal computers to cool the CPU and other electrical/electronic components.
This type of cooling fan has a casing that includes a casing main body with a side radiator and a lid with an aperture formed therein. A fan motor includes a rotor provided with a plurality of fan blades and a stator and is disposed in the casing. Also, an object to be cooled is joined to a base surface of the casing main body and the aperture and radiator form a circulating air flow conduit when the fan motor is driven. As a result, heat generated from the object to be cooled is dispersed and the object is cooled.
Conventional cooling fans exist in which the fan motor is arranged on the side of the lid. However, there are problems with this cooling fan in that the force of the air current is small and therefore the cooling effect is low. Also, conventional cooling fans are noisy and they typically have a casing main body that is thick.
Further, in another conventional cooling fan, the fan motor is arranged on the casing main body and a distal end of a rotational axle of the rotor is installed in the casing main body by perforating the base plate of the casing main body and using a ball bearing or washer. In this type of cooling fan, the cooling effect is diminished because the force of the air current is small and, thus, the cooling effect is low. This type of cooling fan is noisy and its casing main body is thick. Moreover, it has holes for installing the rotational axle of the rotor on the outer side base surface of the casing main body. Because the rotor is installed in the casing main body, an assembly process is required to turn the cooling fan over which reduces productivity of manufacturing.